So, this may sound like a contradiction in terms, but it seems that the gecko is pretty much the best animal version of Spiderman. Most people are aware that it is a pretty impressive climber, but it seems the gecko has a number of things helping it out.
To better understand things, we need to look more closely at their feet, and what we would find is that they have thousands of small hairs all over the surface, and those hairs are going to play a major role in helping them to climb and generally just hang around.
The key is that there is a chemical between the hairs, and it means that they effectively stick to surfaces which allows them to climb and just sit there. It also means that they can hang onto something with just a single toe and still not fear falling off, which you have to admit is pretty impressive.